1 /*****************************************************************************
2  * DynaMechs: A Multibody Dynamic Simulation Library
3  *
4  * Copyright (C) 1994-2001  Scott McMillan   All Rights Reserved.
5  *
6  * This library is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU General Public License
8  * as published by the Free Software Foundation; either version 2
9  * of the License, or (at your option) any later version.
10  *
11  * This library is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14  * General Public License for more details.
15  *
16  * You should have received a copy of the GNU Library General Public
17  * License along with this library; if not, write to the Free
18  * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
19  *****************************************************************************
20  *     File: dmTreadmill.hpp
21  *   Author: Steven Rodenbaugh
22  *  Created: 2000
23  *  Summary: class definition for a dynamic environment with a treadmill
24  *****************************************************************************/
25 
26 #ifndef _DM_TREADMILL_HPP
27 #define _DM_TREADMILL_HPP
28 
29 #include <dm.h>
30 #include <dmObject.hpp>
31 #include <dmEnvironment.hpp>
32 
33 #include <vector>
34 
35 //======================================================================
36 
37 /* Steven Rodenbaugh writes....
38 
39 General Notes:
40 - Might make this be a child a general class like dmMovingEnvironment
41 - Need generalized way to specify environment type -probably change to env file
42 - Need permission from Scott to be using his code?
43 - Need class description here
44 - Should probably add OpenGL support equivalent to rest of DynaMechs
45 
46 - The parsing method follows the same technique utilized in the rest of
47        of DynaMechs (This does have the drawback that there is not a graceful
48        recovery from parse errors.  In the future, that should probably be
49        addressed.)
50 - The information that strictly concerns the graphical representation is
51        included in another file because it does not impact the simulation
52 */
53 
54 
55 //======================================================================
56 
57 /**
58    The treadmill is a dynamic environment requiring simulation to update its
59    state.  It can be thought of as surface with a horizontal velocity
60    component.  It has a length along the direction of motion, width
61    perpendicular in the horizontal plane, and a normal (up) direction.
62 
63    It is derived from {\tt dmEnvironment}, and when hydrodynamics are enabled
64    in the build, this class appends to the base class state vectors.
65  */
66 
67 
68 class DM_DLL_API dmTreadmill : public dmEnvironment
69 {
70 public:
71    ///
72    dmTreadmill();
73    ///
74    virtual ~dmTreadmill();
75 
76    ///
77    void setPosition(const CartesianVector position);
78    ///
79    void getPosition(CartesianVector pos) const;
80 
81    ///
82    void setWidth (Float width);
83    ///
84    Float getWidth() const;
85 
86    ///
87    void setLength (Float length);
88    ///
89    Float getLength() const;
90 
91    // dmSystem functions
92    ///
getNumDOFs() const93    virtual unsigned int getNumDOFs() const
94       {
95          return dmEnvironment::getNumDOFs() + 1;
96       }
97    ///
98    virtual void setState(Float treadmill_pos[], Float treadmill_vel[]);
99    ///
100    virtual void getState(Float treadmill_pos[], Float treadmill_vel[]) const;
101 
102    ///
103    void setVelocityDirection(const CartesianVector v_dir);
104    ///
105    void getVelocityDirection(CartesianVector v_dir) const;
106 
107    ///
108    void setNormalDirection(const CartesianVector normal);
109    ///
110    void getNormalDirection(CartesianVector normal) const;
111 
112    /// These functions should be moved to the loader
113    //void loadConveyorData(const char *filename);
114    ///
115    //const char *getConveyorFilename() const {return m_conveyor_filename;}
116 
117    ///
118    //virtual Float getGroundDepth(CartesianVector contact_pos,
119    //                             CartesianVector ground_normal);
120 
121    ///
122    //virual Float getGroundElevation(CartesianVector contact_pos,
123    //                                CartesianVector ground_normal);
124 
125    // dynamics algorithm
126    ///
127    virtual void dynamics(Float *qy, Float *qdy);
128    virtual void draw() const;
129 
130 protected: // Functions
131    void computeOrientation();
132 
133 private: // Functions
134    dmTreadmill(const dmTreadmill &);
135    dmTreadmill &operator=(const dmTreadmill &);
136 
137 private: // Variables
138    Float m_half_width;
139    Float m_half_length;
140    CartesianVector m_position;
141    CartesianVector m_normal;    // normalized
142    CartesianVector m_forward;   // normalized
143    CartesianVector m_left;      // normalized
144 
145    Float m_q, m_qd, m_qdd;
146 
147    //CartesianVector m_earthz;
148    HomogeneousTransformationMatrix m_eTc, m_cTe;
149 };
150 
151 #endif
152